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In this report we discuss the self-consistent dynamics of pickup ions in the solar wind flow around the lunar-like object. In our model the solar wind and pickup ions are considered as a particles, whereas the electrons are described as a fluid. Inhomogeneous photoionization, electron-impact ionization and charge exchange are included in our model. The Moon will be chosen as a basic object for our modeling. The current modeling shows that mass loading by pickup ions H + , H 2 + , He + , and Na + may be very important in the global dynamics of the solar wind around the Moon. In our hybrid modeling we use exponential profiles for the exospheric components. The Moon is considered as a weakly conducting body. Special attention will be paid to comparing the modeling pickup ion velocity distribution with ARTEMIS observations. Our modeling shows an asymmetry of the Mach cone due to mass loading, the upstream flow density distribution and the magnetic field. The pickup ions form an asymmetrical plasma tails that may disturb the lunar plasma wake.

In this report we discuss the self-consistent dynamics of pickup ions in the solar wind flow around the lunar-like object. In our model the solar wind and pickup ions are considered as a particles, whereas the electrons are described as a fluid. Inhomogeneous photoionization, electron-impact ionization and charge exchange are included in our model. The Moon will be chosen as a basic object for our modeling. The current modeling shows that mass loading by pickup ions Na + and He + may be very important in the global dynamics of the solar wind around the Moon. In our hybrid modeling we use exponential profiles for the exospheric components. The Moon is considered as a weakly conducting body. Special attention will be paid to comparing the modeling pickup ion velocity distribution with ARTEMIS observations. Our modeling shows an asymmetry of the Mach cone due to mass loading, the upstream flow density distribution and the magnetic field. The pickup ions form an asymmetrical plasma tails that may disturb the lunar plasma wake.

In this report we discuss the ion velocity distribution dynamics from the 3D hybrid simulation. In our model the background, pickup, and ionospheric ions are considered as a particles, whereas the electrons are described as a fluid. Inhomogeneous photoionization, electron-impact ionization and charge exchange are included in our model. We also take into account the collisions between the ions and neutrals. The current simulation shows that mass loading by pickup ions H(+); H2(+), CH4(+) and N2(+) is stronger than in the previous simulations when O+ ions are introduced into the background plasma. In our hybrid simulations we use Chamberlain profiles for the atmospheric components. We also include a simple ionosphere model with average mass M = 28 amu ions that were generated inside the ionosphere. The moon is considered as a weakly conducting body. Special attention will be paid to comparing the simulated pickup ion velocity distribution with CAPS T9 observations. Our simulation shows an asymmetry of the ion density distribution and the magnetic field, including the formation of the Alfve n wing-like structures. The simulation also shows that the ring-like velocity distribution for pickup ions relaxes to a Maxwellian core and a shell-like halo.

Titan has a very extensive atmosphere and exosphere which interact strongly with the corotating magnetospheric plasma. Some of the new pickup ions created in the vicinity of the exosphere will re-impact the upper atmosphere causing additional energy input. Previous investigations of the atmospheric collisional interaction of the pickup ions have generally assumed the atmosphere to be spherically symmetric. From the Voyager and Cassini observations, we know that the magnetic field configuration and plasma flow field is highly asymmetric. To study the possible spatial variation in the pickup ion influx, we have employed the plasma data of the three dimensional MHD simulation of Kopp and Ip [Kopp, A., Ip, W.-H. Asymmetric mass loading effect at Titan’s ionosphere. J. Geophys. Res. 106, 8323–8332, 2001] to compute the trajectories of the pickup ions. In this work, we calculate the ion influx and energy deposit into Titan’s exobase for the H2+, CH4+ and N2+ pickup ions separately. The model results of four different Titan’s orbital locations are also presented.

The regions in space plasmas where mass loading occurs are rich environments for the generation of low frequency waves. We discuss wave generation in the interaction regions of Io and Europa with Jupiter's magnetosphere. We contrast processes in these regions with wave generation near comets. Mass loading occurs when neutrals from Io exosphere are ionized and picked up into the plasma torus. Pickup ions have ring distributions able to generate waves. Galileo data showed the existence of ion cyclotron waves in the Io torus with frequencies near the gyrofrequencies of SO 2 + , SO + , and S + ions. Wave location suggests a fan-shaped region of ion pickup extending downstream from Io. In addition, mirror mode waves have been observed in Io's wake. At Europa the mass loaded into the magnetosphere is less than from Io. Galileo observed transverse waves in the wake with frequencies near the gyrofrequencies of O 2 + , and Cl + ions. Wave characteristics indicate that they are ion cyclotron waves generated by pickup ions. Wave power suggests that the pickup ion rate is larger when Europa is near the center of the jovian current sheet than when the moon is outside of it. The dominant mode near these satellites depends on pickup ion composition. Wave properties are not uniform indicating that the spatial distribution of pickup ions is not homogeneous. Wave generation near comets occurs because cometary material is ionized and picked up into the solar wind. The nature of the interaction region and of pickup ions is determined by solar wind properties and the gas production rate of the comet. In contrast to moon–satellite interactions, in this case pickup ions can have a significant parallel drift velocity and more wave modes are unstable. Waves near comets include, H 2 O + ion cyclotron waves, magnetosonic/whistler waves, and mirror mode.

In recent years, two important aspects of heliospheric physics have emerged: (1) the intrinsic dynamism of the Sun's open magnetic flux and its vast importance for energetic particle propagation and acceleration; and (2) the importance of heliospheric grain populations for the production of energetic particles and anomalous cosmic rays. These new aspects have seeded the discovery of the inner and outer pickup ion sources; the discovery of the outer source of anomalous cosmic rays; the discovery that nearly radial magnetic fields in co-rotating rarefaction regions and associated energetic particle dwells are caused by the motions of open magnetic field footpoints across coronal hole boundaries; the relevance of these footpoint motions for ubiquitous statistical acceleration in slow solar wind and for Favored Acceleration Locations at the Termination Shock (FALTS). Here, we review these emerging discoveries and discuss how their combination is leading to a vastly different and improved understanding of our intrinsically dynamic heliosphere.

Ion pickup processes invariably produce anisotropic ion distributions and hence can give rise to wave generation. This paper discusses the waves due to the Io pickup source in Jupiter's magnetosphere. In the near-Io torus, the Galileo spacecraft observed ion cyclotron waves near the sulfur dioxide gyrofrequency, which grow due to the absence of a thermalized background component of these molecular ions in a torus plasma of predominantly dissociated species. These wave observations allow limits on pickup source rates to be estimated. On the edge of the Io wake, mirror mode waves were seen where the pickup ion contribution to the pressure anisotropy is sufficient to overcome the instability threshold. The mirror mode can dominate over the individual ion cyclotron modes in a multi-species plasma. The mass density in the torus cannot increase indefinitely and the plasma must be radially transported through the Jovian magnetosphere. Wave processes may be associated with any ion distribution anisotropies that arise during their radial transport, and with unsteady reconnection processes that may facilitate their eventual loss from the magnetotail.

The nature of the interaction of Io with the Io torus has undergone an important paradigm shift due to the many results of the Galileo flyby and the reinterpretation of the Voyager data. The main obstacle to the flowing plasma appears to be mass loading. Only a small fraction of the flux tubes that are flowing toward Io's cross section at infinity join up with the Io magnetic field and flow slowly across Io's polar caps. The mass pickup on these flux tubes is heated much less than on the tubes that flow near to but around Io. Both Voyager and Galileo data show this deceleration and deflection. The slowed plasma in the wake is accelerated up to corotational velocities by 6 R Io downstream. This picture is much different than the original picture of Io as a unipolar inductor in which an electric potential drop of 500 kV appeared across Io. In fact, the potential drop is only about 50 kV. The current flowing along magnetic field lines in the vicinity of Io, however, is much greater than heretofore believed. The original theories did not take into account the size of the mass-loading region or the closure currents associated with the bent field lines. Thus they assumed that the currents would be limited by the Alfven conductance and the size of Io. The field-aligned current system appears to be much larger than previously proposed and shifted downstream. This downstream shift has important consequences for the possible size of the Io intrinsic field. It may be larger than originally proposed. The location and source of these current systems does not affect their capability of generating the potential drops along the magnetic field that were postulated to be responsible for radio emissions. The low potential drop across Io evidenced by the small fraction of the wake stream lines that intersect Io and the low pickup ion temperature produces cold, slow flowing flux tubes that can interchange with the hot torus tubes just inside the Io orbit, producing the cold plasma torus.

A self-consistent time-dependent cosmic ray-hydrodynamic model is used in spherical symmetry to solve the standard cosmic ray transport equation for combined anomalous and galactic proton transport, and the one-fluid equations for the solar wind/pickup ion fluid including the dynamic effects of cosmic rays. The model calculates the evolution of a single global merged interaction region including its interaction with the heliospheric termination shock, and the consequent effect on cosmic ray modulation. A series of such regions is also simulated to study their combined contribution on the cosmic-ray modulation cycle.